barbasco—a term used for
several plants that contain toxic chemical compounds used by indigenous
populations to poison and catch fish (poisons that kill fish are called “piscicides”).
From the 1950’s until the
1970s there was a vigorous trade in one such fish-killing plant, the inedible, wild Mexican
yam, Dioscorea mexicana. The Mexican yam grows as an annual vine with an above-ground dome-shaped stem (called a “caudex”). The international traffic in Mexican yam was called the Barbasco Trade.
The chemical diosgenin was
extracted from the Mexican yam root. It was used
as a precursor for the synthesis of steroidal hormones such as progesterone,
the basis of the first generation birth
The Barbasco Trade ended when root began to be depleted in the wild and methods were developed to
produce steroids from soy beans.
Word origin: The word “barbasco” is from Latin adjective barbascus, bearded. The Mexican yam is not particularly hairy, so technically the term used for Dioscorea mexicana is a misnomer.